This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The two main goals of this research are first, to understand the cell biological regulation of multidrug efflux transport and second, to probe the roles of these transporters in protection and regulation of embryonic development. This proposal links between two bodies of knowledge, one on the cellular physiology of multidrug efflux transport, primarily examined in the context of cancer and epithelial transport, and another focusing the structural changes in cell surface and membrane organization of embryo development. In this proposal, we will investigate the relationship between cell surface changes in early embryo development and changes in the efflux transporter activity focusing on sea urchins as an easily assayed and manipulated model organism. We will also continue efforts, currently ongoing in the K Phase of this award, to translate findings from the sea urchin to the mouse model, in order to characterize the role of these activity changes in protection of the embryo from potential teratogens encountered during assisted reproduction.